I've done it for years. Make sure you have a good welder fab the hitch. It will put a lot of strain on both the boat trailer as well as the RV. I have had to have both reinforced.
When going somewhere I am less familiar with, I drop the boat in the boat ramp parking lot. Go, park the 5er, go back and get the boat.
I am able to hitch up the boat myself. Just takes a few trips walking back and forth to check things out. If you have a 2nd person with you, much easier.
You can back up if you have to. Not ideal, but possible.
Fuel stations can be trouble. Truck stops are the easiest. I added a 60 gallon aux tank so I don't have to worry about it.
If your boat has much tongue weight, you will get more chucking than you had before. Lighter boats you won't really feel much of anything.
Have you actually weighed your boat? I don't know of a 19' boat that when loaded and on the trailer would be that light. I towed my 21' sterndrive for years. It was 5500 pounds on the trailer. I have a 16' Lund that is somewhere between 2000 - 2500 pounds. Don't really notice it. My new ski boat is a 23' Malibu, and just too heavy to pull tandem.
Here is my old 21' Crownline .
And with my Lund.
Moderator edit to re-size pictures to forum limit of 640px maximum width.